LASTSORT is available since version 1.0.0.
Sorts a list of Geo Time Series™ according to their most recent value. If most recent values are identical, ticks will be compared, the most recent appearing first. If the ticks are also identical, then metadata will be compared, classname first then labels then attributes.
When comparing on metadata, labels and attributes lists are first sort in a lexicographic order, then label values are compared when label names match. Same for the attributes
Use this function to compute Top N queries.